'Personal' is an adjective (private, yours); 'personnel' is a noun (the staff of a company).
"Personal" is an adjective describing something private, individual, or related to you: "personal opinion", "personal space", "personal information".
That's a personal question, I'd rather not answer it.
Please keep your personal belongings with you at all times.
I took a personal day off to handle some family stuff.
"Personnel" is a formal noun referring to the staff of an organization, a more corporate version of "staff" or "employees".
The company hired additional personnel to handle the holiday rush.
Only authorized personnel are allowed in this area.
The military personnel stationed at the base were given new orders.
Common mistake
"The personal department" is a common mistake, especially confusing since it looks so much like "personnel". In English, that department is called "HR" or "the personnel department" / "Human Resources", never "the personal department".
Trick to remember it
"Personnel" has two "n"s and ends like "-nel", similar to "channel" or "tunnel": think of a "channel" of employees within a company. "Personal" has one "n" and is the everyday adjective, like "personal trainer" or "personal space".
Quick rule
Does it describe something of yours, private, or individual? "Personal" (adjective). Is it about an organization's employees? "Personnel" (noun).
Did you know?
Both words come from French "personnel", but English borrowed them at different times and adapted them differently: "personal" arrived first, directly from Latin "personalis", while "personnel" was borrowed from French military usage in the 19th century to refer to a group of soldiers or an organization's staff, keeping the French double "n". That's why "personnel" still looks and sounds "more French" than "personal".
Exercise 1 · Pick the right one
I don't want to talk about my finances at work, it's too _____.
Exercise 2 · Pick the right one
The factory needs more _____ on the night shift to keep up with demand.
Exercise 3 · Form the word
One means to receive or agree to something, the other means to exclude or not include.
'Advice' is the guidance you receive (noun); 'advise' is the act of giving that guidance (verb).
'Affect' is the verb meaning to influence something; 'effect' is the noun meaning result or consequence.
'Aisle' is the walkway between rows of seats or shelves; 'isle' is a small island.
Bryan López
Founder of SpeakUP Academy